The present disclosure relates to force sensors. More particularly, it relates to sensors and related systems for determining magnitude and direction of a force applied to an object, with particular usefulness with relatively small surface area objects such as various surgical instruments.
The need to detect or determine parameters associated with a force applied to an object arises in a plethora of situations. In this regard, force sensors (or load cells) are widely used to measure or monitor the forces of compression, tension, and shear. The two basic components of a force sensor are the sensing element(s) and circuit. The sensing element is oftentimes a strain gauge, which is comprised of a coil; the circuit is the connection of these gauges throughout the force sensor. While conventional force sensors are well-suited for many applications, the constraints associated with certain objects and/or end uses prevents their implementation.
For example, many surgical procedures entail introduction of a surgical instrument into the patient's anatomy. More generally, a distal end of the surgical instrument is inserted into and/or through various portions of the anatomy, and in some instances purposefully brought into contact with an anatomical target site. The caregiver may desire to know the forces being experienced by the distal end (e.g., as the distal end is inserted into the patient, various anatomical structures may be encountered; upon contact of the distal end with an anatomical structure and with further attempts to distally maneuver the surgical instrument, resistance of the anatomical structure to further movement of the distal end creates or applies a force onto the distal end). With the advent of minimally invasive and similar procedures in which only a small incision is made in the skin through which the surgical instrument is introduced, the surgeon cannot readily view a location of the distal end within the patient, let alone estimate forces at the distal end. Further, where the surgical instrument is elongated and/or formed of a relatively flexible or resilient material, forces at the distal end are not directly transferred to the proximal end otherwise being held by the surgeon; under these circumstances, the surgeon cannot rely upon a tactile “feel” at the proximal end to estimate force. Unfortunately, due to the relatively small size of many surgical instruments, conventional force sensors are simply not viable. Similar concerns arise with instruments or objects in many other technical fields.
In light of the above, a need exists for sensors and related systems capable of estimating or determining force experienced by an object to which the sensor is assembled, with particular application to small scale object or end uses.